In the film, Bellatrix casts a blue spell at Ginny Weasley instead of a Killing Curse, who deflects it using a Shield Charm. In the book she just avoids it.
No, we don't know what spell did Molly use to take down Bellatrix, but it certainly wasn't Avada Kedavra. Whatever spell she used, it didn't disintegrate Bellatrix either.
She didn't say any incantation, but she definitely used 2 spells. The first one froze Bellatrix, most likely petrificus totalus as it looked like what happened to Neville when Hermione used that spell on him. Then for the second spell I guess reducto, as this spell shatters things and blasts them into pieces.
After being on the run from a bunch of Snatchers, the gang were taken to Malfoy Manor, where Bellatrix proceeded to torture Hermione using the Cruciatus Curse.
An enraged Molly Weasley engages Bellatrix in a duel and fires a curse that hits Bellatrix right over the heart, killing her.
The plan is to prevent Cedric from winning the Triwizard Tournament and reaching the portkey. They go back in time several times, and on one attempt, Cedric actually ends up attacking Delphini.
Delphini, nicknamed Delphi, is the titular main antagonist of Harry Potter and the Cursed Child. Although she initially introduces herself as the niece of Amos Diggory, Delphi is in fact, the child of Lord Voldemort and Bellatrix Lestrange and has only one goal, restoring her father.
The Killing Curse ('Avada Kedavra')
Obviously there's no coming back from this spell, and according to the Ministry of Magic's classifications (and, again, fake-Moody) this is the worst Unforgivable Curse.
Harry makes use of two of the Unforgivable Curses in the books. Dueling with Bellatrix Lestrange, he attempts the Cruciatus curse, with limited results; Bellatrix says that he has to really hate someone to make the Unforgivable Curses work properly, righteous indignation isn't enough.
Merlin's beard/Merlin's pants
Merlin's beard, Merlin's “baggy y-fronts,” Merlin's pants, or simply just his name are all common curses uttered by the wizarding community in times of surprise or crisis.
Yep, that happened: Bellatrix and Voldemort had sex sometime around Order of the Phoenix or Half-Blood Prince, and their wild night in bed led to a child named Delphi Diggory/Riddle/Lestrange. According to Delphi herself, she was born sometime before the Battle of Hogwarts.
Despite not using her personal wand, Bellatrix still proved herself to be equal in power to the three of them. During the duel, Bellatrix shot a Killing Curse at Ginny. Bellatrix's curse narrowly missed Ginny, sparing her death by mere inches.
Although the curses were seldom discussed in school and are highly illegal, Harry had no choice but to turn to them after he was thrust into the Second Wizarding War. Despite his knowledge of the Avada Kedavra incantation, Harry refused to use the Killing Curse.
This means that the killing curse (if I'm correct) has the power to destroy horcruxes. But when Ron and Hermione are about to die by Nagini, Ron casts the killing curse as a last resort and it simply rebounds off Nagini as it was nothing.
George has his ear cursed off by Severus Snape (by accident), who uses the Sectumsempra curse. When he recovers, he seems in good spirits, making jokes about his new, earless appearance and by saying that at least now their mother will be able to tell them apart.
The Killing Curse was created in the early Middle Ages by Dark witches and wizards. Primarily, the curse was used to quickly slay opponents during a duel. In 1707, the Wizards' Council was restructured into the Ministry of Magic, which allowed for more strict restrictions on certain types of magic.
Dec. 28, 1997: Ron Weasley destroys Salazar Slytherin's locket deep in the Forest of Dean, Gloucestershire, by stabbing it with Godric Gryffindor's sword.
None of the good guys dare use the Killing Curse throughout the events of the movies and books, no matter how high the stakes and how difficult things are. But Ron Weasley is the exception, giving it a go in the Deathly Hallows: Part 2 movie when himself and Hermione look destined to die via Nagini.
Expelliarmus did not beat Avada Kedavra.
Voldemort's wand (the elder wand) recognized its true master (that was Harry) and refused to attack it. In a way Voldemort killed himself as his own spell backfired on him.
The least-used spell: Waddiwasi, used in Harry Potter and the Prisoner of Azkaban, which is “the incantation of a charm that can be used to shoot a small, soft mass of whatever the caster so desires at the target or victim,” according to the Harry Potter Wiki.
Sectumsempra was a curse invented by Professor Severus Snape that lacerates the target and causes severe haemorrhaging. Snape created it as a student of Hogwarts, with the intention of using it against his enemies, likely including the Marauders, and it became one of his specialities.
Delphini's birth was one of the most well-guarded secrets of Voldemort and his servants. She was sent to live with Euphemia Rowle, who only raised her because she was offered gold, though we don't know who paid her.
He's fifteen. He's unable to suss out his own emotions. But on top of that, Albus is named after two men Harry looked up to: Albus Dumbledore and Severus Snape.
Nagini, it turns out, was actually a Maledictus—a witch with a blood curse that turns her permanently into a beast (in her case, a giant snake).